<!DOCTYPE html>
<html lang="en" style="font-size: 19.2px;">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .com-sel {
        line-height: 3rem;
        cursor: pointer;
        /*鼠标上移变成小手*/
    }

    .com-opt {
        /* width: 10%; */
        color: #999;
        /*去掉默认的下拉三角*/
        appearance: none;
        -moz-appearance: none;
        -webkit-appearance: none;
        /*添加下拉三角图标*/
        /* background: url("img/arrow_down.png") no-repeat right center transparent; */
        background:#fff;
        width: 7.55rem;
        height: 1.88rem;
        /* background: #FFFFFF; */
        padding: 0.63rem;
        padding-right: 14px;
        height: 2.28rem;
        border-radius: 0.31rem;
        border: 0.03rem solid rgba(198, 201, 207, 0.36);
    }
</style>

<body>
    <div class="com-sel">
        <select class="com-opt">
            <option value="">查看详情</option>
            <option value="">方形</option>
            <option value="">圆形</option>
            <option value="">锥形</option>
        </select>
    </div>
</body>
<script>
    var signMsg = ''
    console.log(signMsg.length)
    if (signMsg != '' && signMsg.length > 6) {
        console.log('22222')
        } else {
            console.log('55555')
        }
</script>
</html> 